1 files changed, 146 insertions, 0 deletions

diff --git a/src/fseccomp/syscall.c b/src/fseccomp/syscall.c
new file mode 100644
index 000000000..7c2c4cbb2
--- /dev/null
+++ b/src/fseccomp/syscall.c
@@ -0,0 +1,146 @@
+/*
+ * Copyright (C) 2014-2016 Firejail Authors
+ *
+ * This file is part of firejail project
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+*/
+#include "fseccomp.h"
+#include <sys/syscall.h>
+
+typedef struct {
+        char *name;
+        int nr;
+} SyscallEntry;
+
+static SyscallEntry syslist[] = {
+//
+// code generated using tools/extract-syscall
+//
+#include "../include/syscall.h"
+//
+// end of generated code
+//
+}; // end of syslist
+
+// return -1 if error, or syscall number
+int syscall_find_name(const char *name) {
+        int i;
+        int elems = sizeof(syslist) / sizeof(syslist[0]);
+        for (i = 0; i < elems; i++) {
+                if (strcmp(name, syslist[i].name) == 0)
+                        return syslist[i].nr;
+        }
+        
+        return -1;
+}
+
+char *syscall_find_nr(int nr) {
+        int i;
+        int elems = sizeof(syslist) / sizeof(syslist[0]);
+        for (i = 0; i < elems; i++) {
+                if (nr == syslist[i].nr)
+                        return syslist[i].name;
+        }
+        
+        return "unknown";
+}
+
+void syscall_print(void) {
+        int i;
+        int elems = sizeof(syslist) / sizeof(syslist[0]);
+        for (i = 0; i < elems; i++) {
+                printf("%d\t- %s\n", syslist[i].nr, syslist[i].name);
+        }
+        printf("\n");
+}
+
+// allowed input:
+// - syscall
+// - syscall(error)
+static void syscall_process_name(const char *name, int *syscall_nr, int *error_nr) {
+        assert(name);
+        if (strlen(name) == 0)
+                goto error;
+        *error_nr = -1;
+        
+        // syntax check
+        char *str = strdup(name);
+        if (!str)
+                errExit("strdup");
+
+        char *syscall_name = str;
+        char *error_name = strchr(str, ':');
+        if (error_name) {
+                *error_name = '\0';
+                error_name++;
+        }
+        if (strlen(syscall_name) == 0) {
+                free(str);
+                goto error;
+        }
+
+        *syscall_nr = syscall_find_name(syscall_name);
+        if (error_name) {
+                *error_nr = errno_find_name(error_name);
+                if (*error_nr == -1)
+                        *syscall_nr = -1;
+        }
+
+        free(str);
+        return;
+        
+error:
+        fprintf(stderr, "Error fseccomp: invalid syscall list entry %s\n", name);
+        exit(1);
+}
+
+// return 1 if error, 0 if OK
+int syscall_check_list(const char *slist, void (*callback)(int fd, int syscall, int arg), int fd, int arg) {
+        // don't allow empty lists
+        if (slist == NULL || *slist == '\0') {
+                fprintf(stderr, "Error fseccomp: empty syscall lists are not allowed\n");
+                exit(1);
+        }
+
+        // work on a copy of the string
+        char *str = strdup(slist);
+        if (!str)
+                errExit("strdup");
+
+        char *ptr =strtok(str, ",");
+        if (ptr == NULL) {
+                fprintf(stderr, "Error fseccomp: empty syscall lists are not allowed\n");
+                exit(1);
+        }
+
+        while (ptr) {
+                int syscall_nr;
+                int error_nr;
+                syscall_process_name(ptr, &syscall_nr, &error_nr);
+                if (syscall_nr == -1)
+                        fprintf(stderr, "Warning fseccomp: syscall %s not found\n", ptr);
+                else if (callback != NULL) {
+                        if (error_nr != -1)
+                                filter_add_errno(fd, syscall_nr, error_nr);
+                        else
+                                callback(fd, syscall_nr, arg);
+                }
+                ptr = strtok(NULL, ",");
+        }
+        
+        free(str);
+        return 0;
+}